The present invention relates to a drain cleaning machine, and more particularly to a release assembly for removing the rotatable drum from the machine without tools.
Conventional drum type drain cleaning machines typically include a frame structure supporting a rotatable snake drum and a drive motor arrangement for rotating the drum. The frame structure also supports a snake feeding arrangement by which the snake or cable is axially displaced relative to the rotating drum during use of the machine. The snake coiled within the rotatable drum is displaced by the feeding arrangement and inserted into a pipe or drain to be cleaned. Rotation of the drum rotates the snake to achieve such cleaning.
The rotatable drum in known drain cleaning machines may typically be removed from the support frame and drive arrangement to facilitate replacement of the drum with one containing a snake having a different diameter and to make the separate components more mobile. Disadvantageously, conventional removable drums require tools to disassemble the rotatable drum from the support frame. This, of course, requires access to the proper tools and is also somewhat time consuming for the operator. Other known disassembly arrangements require a groove cut in a shaft which mounts the rotatable drum. The groove is located between the rotatable drum and the support frame to receive a spring-loaded pin which rides within the groove. The spring-loaded pin is retracted to disassemble the rotatable drum from the support frame. By its location, the groove reduces the strength of the shaft in a weight bearing segment. Friction between the groove and the single pin may also eventually require the repair or replacement of the disassembly arrangement. Further, the pin must be manually retracted to both install and remove the rotatable drum.
Accordingly, it is desirable to provide a rotatable drum release assembly which provides an effective release without the necessity of tools and which locates shaft grooves in a position to minimize their load bearing effect on the shaft.
The drum release assembly according to the present invention provides a shaft release coupling which telescopically engages a rotary drum shaft to lock and unlock a rotary drum to a drain cleaning machine. No shaft grooves are located in the shaft. Localized weakening of the shaft is thereby prevented.
The shaft release coupling includes a polygonal shaped distal end which corresponds with a polygonal opening in the removable drum shaft. At least one of the plurality of faces which form the polygonal shaped distal end includes a retractable engagement member. The retractable engagement member corresponds to a recess located in each face of the polygonal opening. By pressing on a release to overcome the bias of a biasing member, the retractable engagement member retracts into the shaft release coupling.
A removable thrust bushing is preferably mounted about the shaft release coupling between a radially extending flange and the end of the shaft receiving sleeve to reduce friction therebetween. The thrust bearing absorbs thrust produced as the snake is extended from the drum by the feed assembly. Longevity of the shaft release coupling is thereby improved.
To mount the removable drum, the drum shaft is located into one end of the sleeve. Once the shaft is accessible on the opposite side of the sleeve, the release is pressed inwardly and the polygonal shaped distal end is located into the polygonal opening. Once the retractable engagement member reaches the recess in the polygonal opening face, the biasing member drives the retractable engagement member into the recess. The drum is thereby rotatably locked in place.
To remove the drum, the release is pressed inwardly and the shaft release coupling is removed from the shaft. The shaft may then be slid out of the sleeve to remove the drum.
The present invention therefore provides a rotatable drum release assembly which provides an effective release without the necessity of tools and which eliminates shaft grooves and their reduced load bearing effect on the shaft. The present invention further provides a rotatable drum release assembly that has superior thrust capacity and a readily replaceable thrust washer.